1. Field of the Invention
The present invention relates to a unit tile pack manufacturing apparatus for continuously manufacturing unit tile packs each having a plurality of tiles with joints therebetween and interconnected by connecting sheets. More specifically, the present invention relates to a unit tile pack manufacturing apparatus for continuously manufacturing combination unit tile packs, i.e., unit tile packs each having a plurality of arranged tiles.
Note, the term "unit tile pack" denotes an aggregate of a plurality of tiles formed by arranging the tiles in lines and rows with straight longitudinal and lateral joints therebetween and applying a connecting sheet to the front or back of the aggregate. Such a unit tile pack facilitates manual tile work.
2. Description of the Related Art
Conventional tile pack manufacturing apparatuses for manufacturing unit tile packs have been proposed, which comprise mechanisms including an adhesive applying unit and a connecting sheet supplying unit disposed along the tile conveying direction of a tile conveying passage. The adhesive applying unit applies an adhesive over the upper surface or on part of the upper surface of tiles aligned with joints therebetween. The connecting sheet supplying unit supplies connecting sheets to the tiles at points where the adhesive is applied in order to interconnect the adjacent tiles.
In such a conventional unit tile pack manufacturing apparatus, the various problems that occur usually originate in the adhesive applying unit, and hence, the adhesive applying unit is a source of undesirable stoppages in the flow of a tile pack manufacturing line. For example, in the conventional adhesive applying unit, plurality of tiles are conveyed along a tile conveying passage in a pallet having tile receiving pockets for holding the tiles in edge-alignment. The application roller of the adhesive applying unit comes into contact with the entire area of the surface of each of the tiles aligned in the tile receiving pocket to apply an adhesive to the surfaces of the tiles. However, since tiles are maunufactured through a plurality of heating processes having different temperature levels, such as burning and drying, errors in the size of the tiles including thickness, occur. Therefore, when the tiles are disposed in place in the pallet, the upper surfaces of the tiles are not flush and form an irregular plane. Accordingly, each of the tiles comes into contact with the application roller to a varying degree, and hence it is impossible to apply the adhesive to the surfaces of the tiles as a film having a uniform thickness. Furthermore, the size of the tile receiving pockets of the pallet is slightly greater than the maximum external size of the tiles. Accordingly, the tiles are disarranged, i.e., not correctly edge-aligned, when the adhesive is applied to the upper surfaces of the tiles by the application roller. Therefore, in the conventional unit tile packet manufacturing process, it is necessary to check and correct the arrangement of the tiles both before and after the application of the adhesive.
To eliminate the above drawbacks, an adhesive applying mechanism was proposed having a lifting board capable of moving vertically in an area above a tile conveying passage and in an area above an adhesive tank disposed beside the tile conveying passage. This adhesive applying mechanism applies an adhesive to the tiles by absorbing adhesive contained in the adhesive tank and then bringing the adhesive into contact with a tile pack after moving the tile pack on the tile conveying passage. However, this adhesive applying mechanism still applies an adhesive to tiles through contact with the tiles, and thus is unable to eliminate all of the drawbacks of the above-mentioned adhesive applying unit. Furthermore, since the surface of the adhesive contained in the adhesive tank is exposed to the atmosphere, this adhesive applying mechanism has another drawback in that the surface of the adhesive contained in the adhesive tank hardens. Still further, since the adhesive tank must be disposed beside the tile conveying passage, a wide floor space is required for the installation thereof. Furthermore, the tile conveying passage must be stopped while the lifting board moves between the adhesive tank and the tile conveying passage and therefore, the overall operating efficiency of the unit tile pack manufacturing apparatus including this adhesive applying mechanism is extremely low.
Also, in the manufacture of tile packs, unit tile packs are classified into pattern unit tile packs and solid color unit tile packs. In particular, solid color unit tile packs of the same solid color suffer from variation in color tone due to various causes, such as variation of the material in particle size distribution, variation of the material due to segregation in the hopper, or differences between the positions of tiles in the kiln.
Accordingly, if unit tile packs consisting of tiles of different lots differing from each other in color tone but of the same basic color, are laid over a wide area, such as a ceiling, wall or floor of a building, this wide area varies in color tone from section to section which deteriorates the aesthetic appearance of the area.
The usual procedure for obviating this deterioration of aesthetic appearance is to form a unit tile pack by manually selecting individual tiles from different lots and arranging the selected tiles in the form of a unit tile pack; which procedure is inefficient and requires a high degree of skill.